转炉炼钢工艺极限碳排放研究进展

Research progress of ultimate carbon emission in BOF steelmaking process

中国钢铁行业发展取得长足进步,年钢产量连续多年位居全球第一,由此带来的CO_(2)排放等环保压力也日益凸显。降低钢铁行业CO_(2)排放至关重要。长流程炼钢工艺的吨钢CO_(2)排放量约为短流程炼钢工艺的3.5倍,如何降低长流程炼钢碳排放对钢铁工业的低碳发展具有重要意义。提出转炉炼钢极限碳排放工艺技术,从“低碳铁水”、“低碳冶炼”和“低碳原料”3个方面,研究分析长流程-转炉炼钢工艺的减排能力及潜力。在低碳铁水生产方面,依据现有可能实现的技术,铁水生产的碳排可由当前吨铁水碳排1.7 t/t降低至0.8 t/t;在低碳原料方面,转炉炼钢工序生产所需原辅料极限碳排放可由当前吨钢碳排197.5 kg/t降至61.7 kg/t;转炉炼钢工序采用低碳冶炼单元技术,吨钢碳排将显著下降,转炉采用20%废钢和50%废钢,吨钢极限碳排将降低至727 kg/t和466 kg/t。转炉炼钢工序使用50%废钢冶炼,喷吹生物质、采用绿电、低碳原料,转炉工序碳排放强度将从107 kg/t降至-186 kg/t,实现转炉工序“负碳炼钢”;精炼、连铸等工序着眼绿色低碳技术,有望实现炼钢厂“近零碳排”。以转炉为主的长流程低碳炼钢的研究对整个钢铁工业的低碳发展具有重大促进作用,是推进钢铁行业绿色低碳转型、落实“双碳”目标的有力手段。

China′s steel industry has made great progress,and its annual steel output ranks first in the world for many years.The resulting environmental pressure such as CO_(2)emission has become increasingly prominent.It is very important to reduce CO_(2)emission in steel industry.The CO_(2)emission per ton of steel produced by long process steelmaking is about 3.5times that produced by short process steelmaking.How to reduce the carbon emission of long process steelmaking is of great significance for the low-carbon development of the steel industry.The ultimate carbon emission technology of converter steelmaking is proposed,the emission reduction capacity and potential of the long process steelmaking from three aspects of"low carbon hot metal","low carbon smelting"and"low carbon raw materials"is studied and analyzed.In terms of low-carbon hot metal production,according to the existing technology that can be realized,the carbon emission of hot metal production can be reduced from 1.7t/t to 0.8t/t per ton of hot metal.In terms of low-carbon raw materials,the ultimate carbon emission of raw and auxiliary materials required for production of converter steelmaking process can be reduced from 197.5kg/t of current carbon emission per ton of steel to 61.7kg/t.Low carbon smelting technology is adopted in converter steelmaking process,and carbon emission per ton of steel will be significantly reduced.If 20%scrap and 50%scrap are used in converter,the ultimate carbon emission of converter will be reduced to 727kg/t and 466kg/t steel.50%scrap steel is used in converter for smel-ting,biomass is injected,green electricity and low-carbon raw materials are used,and the carbon emission intensity in the converter process will be reduced from 107kg/t to-186kg/t,thus realizing"negative carbon emission steel-making"in the converter process.Refining,continuous casting and other processes focus on green low-carbon tech-nology,which is expected to achieve"near zero carbon emission"in steel mills.The research on long-process low-carbon steelmaking based on converter has a significant role in promoting the low-carbon development of the whole steel industry,and is a powerful means to promote the green and low-carbon transformation of the steel industry and implement the"double-carbon"goal.